The invention relates to a textile fabric for wound care.
For the textile covering of wounds, it is conventional practice to use textile fabrics based on woven, knitted or non-woven fabrics, as well as combinations thereof.
A wound dressing must protect the wound from infection and aid healing and an ideal dressing or bandage material has the following characteristics:
(a) high absorptivity and porosity, because liquid accumulations provide ideal conditions for colonization by germs and for infection of a wound, PA1 (b) must not cause heat accumulation, i.e. the temperature in the vicinity of the wound must not be increased due to the dressing, PA1 (c) is subject to minimum tensile strength, particularly wet tensile strength, PA1 (d) must be easily applicable and sterilizable by known methods, PA1 (e) must conform readily and easily to the wound without folds or creases, and not have any shrinking tendency, PA1 (f) must be physiologically impeccable, i.e. non-irritating, PA1 (g) must be permeable to air and in particular the pore size of the textile fabric must be in a given relation to the thread thickness. If the pore size is too small, accumulation of secretion, sticking of the wound and air exclusion will occur. PA1 (1) high absorptivity, high liquid retention capacity, PA1 (2) high stability in dry and wet state, PA1 (3) high bulk elasticity, good cushioning effect, PA1 (4) high permeability to air and water vapour, PA1 (5) good plastic conforming capacity, PA1 (6) versatile use and at the same time very inexpensive, PA1 (7) chemical purity.
For wound covering purposes, it is known to use gauze dressings of wide-meshed fabric made of cotton, viscose or a combination thereof and for covering the wound, the gauze is folded in multilayer compresses of different size and thickness. Gauze dressings made from pure cotton have proved satisfactory as a wound care material for many decades and are still the most commonly used dressing material due to their high economy and due to the reasons given hereinafter:
However, the wound covering using pure gauze dressings does not satisfy all properties required of such a dressing. In the case of sticking and encrustation, accumulations of secretion can occur and when removing such a stuck dressing, the fresh granulations and epithelial edges are torn open so that once again bleeding, injury and pain occur. When changing a dressing which is sticking to the wound, the wound is torn open again and thereby the healing process is disturbed and interrupted. Gauze dressings are generally available in bulk form of 40 meters length and in various widths and are mainly used for transformation into compresses, swabs, stomach coverings, etc. A prefabricated form is zig-zag gauze or conditioned and/or mechanically compressed, folded material on rolls in socalled dispensers. In conventional gauze compresses which are e.g. 4-ply, 6-ply, 8-ply, 12-ply and 16-ply, the cut edges are folded into the body of the compress so that during the folding procedure fibre residues are prevented from escaping and getting into the wound.
Apart from gauze dressings, wound-friendly dressings are known, such as those with a movement effect. By using varingly twisted and thick threads, a textile fabric is produced by weaving or knitting from pure viscose which reacts to water and liquid secretion by bending and moving. Due to this movement effect, under the action of liquid the fabric is raised from the wound in tunnel-like manner and prevents sticking. Thus, sticking of the textile threads to the wound is prevented by lift-off action, i.e. purely mechanically.
DE-A-22 61 889 discloses a compress, particularly for medical, surgical and other uses, in which a mesh strip is used as a basis, being produced in such a way on a mesh loom that said strip provides edges and an air-permeable, open texture with small, lengthwise extending warp threads which are interconnected by cross threads, the strip or the superimposed strips with edges being cut to the appropriate length and folded back in such a way that a compress in the required measurements is being formed. Such a compress is intended to eliminate any risk of separating into fibres. This compress is a gauze-like knitted fabric, in which the escape of fibre fragments is to be prevented by so-called blocked meshes. The technical physical and chemical characteristics are largely identical with those of gauze dressings.
DE-A-14 92 434 discloses a wound dressing material comprising a knitted textile fabric, in which a thick thread is linked by a looped thin thread, in which the thick thread is highly twisted, straight or in slightly displaced stationary weft and is linked by at least one thread with minimum twist. Due to the fact that this wound dressing material has different yarn dimensions and twists, the thread shortens when wetted so that the dressing material is raised off the wound surface. This leads to a non-stick effect. As a result of the relatively dense thread structure, said wound dressing material can only be used to a limited extent as a compress, due to lack of plasticity.
DE-A-32 13 673 describes a wound dressing material, particularly for adhesive first aid dressings with the special aim of permitting the gentle changing of the dressing. This constitutes an atraumatic wound dressing material. The special feature achieved by said material results from a combination between hydrophobic polyester fibres on the wound side and highly absorbent rayon staple yarns in a textile compound structure.
Another group of textile wound dressings is constituted by non-woven fabrics, in the form of a fibre compound, the individual fibres being mechanically, thermally or chemically interconnected. In most cases viscose fibres are used for such textile fabrics. The strength of such textile fabrics is extremely low due to the fibre compound and material used. In particular, the wet tensile strength is well below that of woven and knitted fabrics. The bulk elasticity is also low. The problem of protruding fibres can only be solved by an additional treatment with synthetic resin dispersions or by laminating of perforated films.
In addition, a number of combined wound dressing materials based on gauze dressings are known, such as e.g. cotton wool/gauze or cellulose/gauze compresses. The water holding capacity of such compresses is increased by the cellulose or cotton wool part serving as the inner absorbent body, but the gauze layer is in contact with the wound and it is not possible to prevent sticking between gauze layer and wound.
The present invention is solving the problem to provide an open-pore, air-permeable, knitted textile fabric not sticking to the wound with dressing gauze-like, but improved characteristics, which ensures maximum wound rest and which when folded represents a wound compress with a hydrophobic covering layer which is in contact with the wound and with hydrophilic absorbent layers located above the same and which in addition has a higher minimum tensile strength compared to dressing gauze.